Top speed on gz250

[Skunkhome]

I have been searching but must be using the wrong search criteria. I am a big guy (250lbs but loosing) and am generally happy with what I believe to be a Stock GZ250. Performance seems to be fine as it keeps up well with surface street traffic (well actually can run off and leave most autos in traffic if I have a mind to do so.) but I am curious as to just what sort of top speed is typical of a stock bike with a lard bucket like me onboard. What is the benefit of adding a 16T front sprocket. I realize that it woud move my shift points up by 6-7% but other than that would it improve my top speed or just reduce the maximum RPM in overdrive (5th gear). I am quite pleased with the amount torque the bike has now and am concerned that the 16t sprocket might reduce the torque significantly. Another issue is that i do not want to adversly effect my gas mileage. Can the 16T sprocket be installed with the stock chain ?

[minieggroll]

I am 5' 8" and 140 lb. I can get up to 65 and even 70 if you give me a couple minutes lol. However, 65 on this bike isn't the most comforting speed in the world to be at imo. By the way, for your sprocket question, I refer you to this thread.

viewtopic.php?f=9&t=4505

There have been many other threads discussing the pros/cons.

[blaine]

The 16t lowers your Rpm,the down side is you loose any usable torque for hills and wind It works well in town as it makes 1st gear much more useable.It worked well for me,but I'm only 150 Lbs wet.You can use the stock chain.So if you try it & don't like it,it's only a few minutes to shift back.
:cool:

[jonathan180iq]

Out of the box, the GZ can touch +/-80mph.

With proper tuning and favorable conditions, it can do just a little more. But not only it is restricted here by power, you're also looking at redline with the factory gearing. The 16T sprocket increases the gearing of the final drive, theoretically giving you room to go faster. But the limited power then cannot overcome the taller gear to use it. There have been some guys who spent a lot of time trying to increase power along with the higher gearing. What's the magical new top speed you ask? ......+/-80mph.

The bike is what it is.

I loved the 16T sprocket because it gave more around-town smoothness to the shifts and I think is just so pleasurable for back country roads. My max speed dropped down to around 75 or so but that still let me cruise on the interstates between different parts of town. What is 5 mph anyway when we're never really on the highway to begin with?

To answer your question, at your size, you should still push 70. More with a tail wind.

[Skunkhome]

I am not dissatisfied with the performance just curious about what is possible.

My stats are as follows:
Driver weight: 240 + lbs
Local elevation: 23-25 ft above sea level.
Fuel: unleaded 87 pump octane
Fuel economy: average 75.6 mpg until last fillup that was 66 mpg with exclusive city driving.
Top speed thus far: 70 mph

[Water Warrior 2]

Originally Posted by Skunkhome

I am not dissatisfied with the performance just curious about what is possible.

My stats are as follows:
Driver weight: 240 + lbs
Local elevation: 23-25 ft above sea level.
Fuel: unleaded 87 pump octane
Fuel economy: average 75.6 mpg until last fillup that was 66 mpg with exclusive city driving.
Top speed thus far: 70 mph

Sounds like a GZ doing what it was meant to do.

[jonathan180iq]

It seems like what you are getting is about what is standard.

I averaged just over 68 mpg for the life of the bike. And I was able to pull a faster top speed with 5/6th throttle. Absolute full twist would slow me down just a bit. That little bit of information right there shows you the importance of proper jetting.

Anything other than 87 octane is a waste on this bike.

[Jvacustoms]

Originally Posted by Skunkhome

I am not dissatisfied with the performance just curious about what is possible.

My stats are as follows:
Driver weight: 240 + lbs
Local elevation: 23-25 ft above sea level.
Fuel: unleaded 87 pump octane
Fuel economy: average 75.6 mpg until last fillup that was 66 mpg with exclusive city driving.
Top speed thus far: 70 mph

Only thing I can suggest to make this bike go any faster is to loose weight and tuck yourself like you are on a crotch rocket, loose the windshield and keep your knees in. Use non-ethanol fuel. add roots blower or some other forced induction. However without major modifications to the engine you will not peak 85mph I only ever achieved 83 mph down hill drafting a truck on the interstate tucked in with non ethanol fuel, no windscreen and fresh tires.

P.s. I weight 245, not picking on you just saying that it is over average intended rider spec. :rawk:

I have went from 250 to 1200 and i love every bit of it. I lost about 12 mpg but with performance and weight that happens... my bike pushes 95 hp form factory that is alot more than a gz and it still wont peak 130mph at any configuration without major modifications. 1984 Gl1200 Goldwing Custom(Naked)

[Skunkhome]

Not loosing the windshield just got it to where I can ride and keep my head out of the airstream. The wind noise was deafening.

[PimpS]

Mine went 120 km/h, thats 74 mph. It was strong back wind, otherwise it goes 115 kmph, thats about 71 mph...
Otherwise i'm a happy camper at 55mph...